Addition of Molybdenum on Ni Resist 1 1

[Shibuz]

Hi,
What would the addition of Molybdenum to NiResist 1 do? If Moly is to added, what wt% is necessary to make a difference?
Thanks,
S Zach

 

[EdStainless]

What are you trying to achieve?

I didn't have much luck improving the corrosion resistance by adding Mo to a Type 1 or 2. We ended up moving to a type 4 ductile.
You need to make sure that the alloy stays fully austenitic. And, like higher Cr, adding Mo will increase hardness and hurt machinability. Though a good anneal of the castings will help.

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Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[metengr]

The web site below is from the Ductile Iron Society and mentions that up to 1% Mo added to Ni-Resist castings improves elevated temperature creep strength;

http://www.ductile.org/didata/Section5/5intro.htm#Table5_4

High Temperature Properties

"Table 5.7 summarizes the high temperature mechanical properties of the various Types of Ductile Ni-Resist Irons. Creep data for these materials are shown in Figure 5.9, with those of CF-4 stainless steel included for reference. The addition of 1% molybdenum to Ductile Ni-Resist increases the high temperature creep and rupture strengths of Types D-2, D-3 and D-5B to the extent that their creep and rupture properties are equal or superior to those of cast stainless steels HF and CF-4. Figure 5.10 shows the short-term, tensile properties of type D-2 from room temperature to 1400oF (760oC). It is interesting to note that there is no temperature range in which embrittlement occurs, and that yield strength does not decrease appreciably until temperatures exceed 1200oF (650oC)."

 

[Shibuz]

Friends,
Thanks for the help.
S Zach